Process for breaking petroleum emulsions



Patented July 21, 1942 PROCESS FOR. BREAKING PETROLEUM EMULSION S Melvin De Groote, University City, and Bernhard Keiser, Webster Groves, Mo.,

assignors to Petrolite Corporation, Ltd., Wilmington, Del., a corporation of Delaware No Drawing. Application October 20, 1941, Serial No. 415,762

8 Claims.

This invention relates primarily to the treatment of emulsions of mineral oil and water, such as petroleum emulsions, for the purpose of separating the oil from the water.

One object of our invention is to provide a novel process for resolving petroleum emulsions of the water-in-oil type, that are commonly referred to as cut oil, roily oil, emulsified oil, etc., and which comprise fine droplets of naturally-occurring Waters or brines dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion.

Another object of our invention is to provide an economical and rapid process for separating emulsions which have been prepared under controlled conditions from mineral oil, such as crude petroleum and relatively soft waters or weak brines. Controlled emulsification and subsequent demulsification under the conditions just mentioned is of significant value in removing impurities, particularly inorganic salts, from pipeline oil.

The demulsifier or demulsifying agent employed in our process, consists of. a quaternary compound of the pyridine series of the kind hereinafter described in detail. Members of the pyridine series suitable as reactants include pyridine, alkylated derivatives of pyridine, particularly alkylated derivatives in which the alkyl radical contains three carbon atoms or less, and especially, methylated pyridines, i. e., pyridines in which one, two, or three methyl groups have been substituted in the nucleus, such as picolines, lutidines and collidines. Also suitable as reactants are the comparable quinolines and isoquinolines, along with C-methyl homologs thereof. Coal tar bases represent mixtures of suitable heterocyclic materials which may be used as such, or after suitable purification, without separation into the individualcomponents.

Specifically, then, the compounds herein contemplated consist of the quaternary ammonium salts obtained by reacting the salt of a tertiary base selected from the group consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof, with formaldehyde and an acid amide of the general formula RCONH2, wherein R stands for an aliphatic hydrocarbon radical.

The method of manufacturing such com- Pounds is well known. For instance, reference'is made to U. S. Patents No. 2,125,901, dated August 9, 1938, to Evans et al., and No. 2,146,392, dated February '7, 1939, to Baldwin et a1. Note that the reactions employed for the production of such compounds are frequently conducted in the presence of a free tertiary base corresponding to said salt. f

It is well known that certain monocarboxy organic acids containing eight carbon atoms or more, and not more than 32 carbon atoms, are characterized by the fact that they combine with alkalis to produce soap or soap-like materials. These detergent-forming acids include fatty acids, resin acids, petroleum acids, etc. For the sake of convenience, these acids will be indicated by the formula R.COOH. Certain derivatives of detergent-forming acids react with alkali to produce soap or soap-like materials, and are the obvious equivalent of the unchanged or unmodified detergent-forming acids; for instance, instead of fatty acids, one might employ the chlorinated fatty acids. Instead of the resin acids, one might employ the hydrogenated resin acids. Instead of naphthenic acids, one might employ brominated naphthenic acids, etc.

The fatty acids are of the type commonly referred to as higher fatty acids; and of course, this is also true in regard to derivatives of the kind indicated, insofar that such derivatives are obtained from higher fatty acids. The petroleum acids include not only naturally-occurring naphthenic acids, but also acids obtained by the oxidation of wax, paraifin, etc. Such acids may have as many as 32 carbon atoms. For instance, see U. S. Patent No. 2,242,837, dated May 20, 1941, to Shields.

Although any of the high molal monocarboxy acids can be converted into amides readily by reaction with ammonia, or by reactions involving the esters thereof with ammonia, it is our preference to employ amides derived from the higher fatty acids, rather than from petroleum acids, rosin acids, wax acids, and the like.

We have found that by far the most effective demulsifying agents are obtained from unsaturated fatty acids having 18 carbon atoms. Such unsaturated fatty acids include the fatty acids, such as oleic acid, ricinoleic acid,'1inoleic acid, linolenic acid, etc. One may employ mixed fatty acids, as, for example, the fatty acids obtained from hydrolysis of cottonseed oil, soyabean oil, corn oil, etc. Our preferred demulsifier is ob: tained from unsaturated fatty acids, and more especially, unsaturated fatty acids containing a hydroxyl radical, or unsaturated fatty acids which have been subjected to an oxidation .or oxyalkylation step, such as oxyethylation.

In view of what has been said, and particularly by reference to the aforementioned patents, it will the following formula:

in which the acyl radical RC is derived from a monocarboxy detergent-forming acid having at least 8 carbon atoms and not more than 32 carbon atoms; and DEN represents a heterocyclic compound of the pyridine series consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for the monovalent anion of an acid, most suitably chlorine, iodine, or bromine, but may be any of the various anions indicated in the two patents previously referred to. A demusifying agent of the kind herein employed may be exemplified by the following examples. These examples are described specifically in the aforementioned U. S. Patent No. 2,146,392, dated February '7, 1939, to Baldwin et al., insofar that the method of manufacture is given in complete detail. The examples themselves will be indicated by formula only. In some instances the variants will be indicated, which can be obtained by obvious modifications of a specific procedure set forth in said Baldwin et al. patent:

Example 1 o.so3H

Example 2 Example 3 Example 4 Example 6 Examples similar to the previous examples are prepared from materials such as oleoamide, ricinoleoamide, amides produced from mixed unsaturated fatty acids, such as fatty acids derived from soyabean oil, teaseed oil, sunflower seed oil, etc.

Example 7 An amide is derived from a drastically oxidized castor oil having the following characteristics:

Such amide is employed in the same manner that stearamide is employed.

be noted that the compounds of the type herein Example 8 One pound mole of castor oil is treated with three pound moles of ethylene oxide in the presence of one-half of one percent of sodium ricinoleate as a catalyst at a temperature of -200 C. at a gauge pressure of 100 pounds and less than 300 pounds, so as to produce an oxyethylated triricinolein. An amide derived from such -oxyethylated triricinolein is employed instead of the amide described in Example 1, preceding.

Example 9 Phenylstearic acid is prepared in any suitable manner, as, for example, in the manner described in U. S. Patent No. 2,081,075, dated May 18, 1937, to Vobach. This is converted into phenylstearic hydroxymethyl amide, and such amide employed in the manner described in Example 1, preceding.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water; petroleum hydrocarbons, such as gasoline, kerosene, stove oil; a coal tar product, such as benzene, toluene, xylene, tar acid oil, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such as methyl alcohol, ethyl alcohol, denatured alcohol,'propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride, sulfur dioxide extract obtained in the refining of petroleum, etc., may be employed as diluents. Similarly, the material or materials employed as the demulsifying agent of our process may be admixed with one or moreof the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone, or in admixture with other suitable well known classes of demulsifying agents.

It is well known that conventional demulsifyinging agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively limited oil solubility. However, since such reagents are sometimes used in a ratio of l to 10,000 or 1 to 20,000, or even 1 to 30,000, such an apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or materials employed as the'demulsifying agent of our process.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our process is based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that the particular demulsifying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned; but we have found that such a demulsifying agent has commercial value, as it will economically break or resolve oil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

In practising our process, a treating agent or demulsifying agent of the kind above described is brought into contact with or caused to act upon the emulsion to be treated, in any of the various ways, or by any of the various apparatus tion with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

A somewhat analogous use of our demulsifying agent is in the removal of aresidual mud sheath which remains after drilling a well by the rotary method. Sometimes the drilling mud contains added calcium carbonate or the like to render the mud susceptible to reaction with hydrochloric acid or the like, and thus expedite its removal.

Attention is directed to our co-pending application for patent Serial No. 401,375, filed July 7, 1941, which subsequently matured as U. S. Patent No. 2,273,181, dated February 17, 1942.

Such co-pending application contemplates resolution of petroleum emulsions of the Water-inoil type by means of demulsifiers of ,the following formula type:

Halogen in which the acyl radical RC0 is derived from a monocarboxy detergent-forming acid having at least 8 carbon atoms and not more than 32 carbon atoms; and DEN represents a heterocyclic compound of the pyridine series consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof. The halogen, of course, is most suitably chlorine orbromine; but iodine may be employed except for its excessive cost. Most correctly DEN is contemplated as a radical,

rather than a compound.

Attention is also directed to our co-pending applications, filed the same date as the-instant application, and bearing the following Serial Numbers 415,763, 415,764,.415,765 and 415,766.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifier comprising a chemical compound of the following formula typez in which the acyl radical RC0 is derived from a monocarboxydetergent-forming acid having at least 8 and not more than 32 carbon atoms; and DEN represents a radical derived from heterocyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for the monovalent anion of an acid.

2. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsip in which the acyl radical RC0 is derived from a higher. unsaturated fatty acid having at least 8 3 fier comprising a chemical compound of the following formula type:

in which the acyl radical RC0 is derived from a monocarboxy detergent-forming acid having at least 8 and not more than 32 carbon atoms; and DEN represents a radical derived from a heterocyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for a halogen.

3. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifier comprising a chemical compound of the following formula type:

in which the acyl radical RC0 is derived 'from a monocarboxy detergent-forming acid having at least 8 and not more than 32 carbon atoms; and

DEN represents a radical derived from a.heterocyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for chlorine.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in sllbjecting the emulsion to the action of a demulsifier comprising a chemical compound of the following formula type:

in which the acyl radical RCQ is derived: from a higher fatty acid having at least 8 and not more than 32 carbon atoms; and DEN represents a radical derived from a heterocyclic compound of the pyridine series, consisting of pyridine, quincline, isoquinoline,. and C-methyl homologues thereof; and X stands for chlorine.

5. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifier comprising a chemical compound of the following formula type:

CHrNILO C.R

and not more than 32 carbon atoms; and DEN represents a radical derived from a heterooyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands'for chlorine.

6.. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifier comprising a chemicalcompound of the following formula type:

in which are acyl radical RC0 is a ricinoleyl radical; DEN represents. a radical derived from a heterocyclic compound of the pyridine series,

consisting of pyridine, quinoline; isoquinoline,

and C-methyl homologues thereof; and X stands for chlorine.

.7. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifler comprising a chemical compound of the following formula type:

cHr-NRoQP.

in which the acyl radical RC0 is an oleyl radical; DEN represents a radical derived from a heterocyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for chlorine.

8. A process for breaking petroleum emulsions 7 in which the acyl radical RC0 is a linoleyl radical; DEN represents a radical derived from a heterocyclic compound of the pyridine series, consisting of pyridine, quinoline, isoquinoline, and C-methyl homologues thereof; and X stands for chlorine.

MELVIN DE GROOTE. BERNHABD KEISER. 

